Magnetic bearings have been known for a long time in the prior art, and allow the contactless arrangement of two bearing parts relative to each other. In particular, because of the negligibly low friction between the bearing parts, a rotor can thus be provided with which the achievable rotation speeds are higher than those normally achievable with plain or roller bearings.
To create a magnetic bearing, typically magnets, e.g. permanent magnets and/or coils, are integrated in the rotor and a stator of the magnetic bearing. Coils can usually be operated simply by application of an electrical voltage. Because of the use of coils supplied with an electrical voltage, in the event of a power failure, for example, there is a risk that the rotor will break away from its contactless arrangement relative to the stator and destroy the bearing. For safety reasons, the magnetic bearing usually therefore has a back-up device which captures the rotor in such a scenario.
Usually, this back-up device is arranged filling the installation space, in particular between the outer ring and the inner ring, which hinders integration in other components. Also, the high energy requirement for a magnetic bearing is in many cases decisive for the use of a roller bearing or a plain bearing instead of a magnetic bearing, although the magnetic bearing is typically superior to the roller bearing or plain bearing in terms of wear, noise generation and achievable rotation speeds.
Thus a need exists for a magnetic bearing that is configured compactly, and the efficiency of which is improved relative to magnetic bearings known from the prior art.